In addition to lapidary use, these drum sanders are excellent for many metalworking applications such as spure removal and contour sanding. The drum expands as the wheel rotates, holding the belt firmly in place. Slightly cushioned sanding surface makes smoothing and shaping of contoured surfaces quick and easy. Pop-out bushings included–adjust to 1/2, 5/8, 3/4 or 1 arbor holes.

Source: Rubber Expanding Drum with Pop-Out Bushing, 8 x 3